To boost the braking force in hydraulic brake systems, use is made of brake force boosters, wherein a pneumatic or vacuum-type brake force booster is a very widely used, reliable and inexpensive solution.
To generate a vacuum for a pneumatic brake force booster, the interior of which is divided into at least one vacuum chamber and one working chamber, negative pressure is required. In many cases, the required negative pressure can be ensured by means of a connection of the vacuum chamber to an intake pipe of a naturally aspirated internal combustion engine. In the case of diesel, turbocharged or electric drives, and in the presence of an increased braking force demand for example owing to higher vehicle weights, the supply of negative pressure cannot be adequately provided, or cannot be provided at all, by the vehicle drive. To reliably ensure an adequate supply of negative pressure, dedicated vacuum pumps are used which draw residual air out of the vacuum chamber of the brake force booster and discharge said air into the atmosphere.